Power cut: how long does freezer food stay safe?

Keep the door shut. The cold stays inside.

The answer in 2 lines. Keep the freezer and fridge doors shut: a full freezer that stays closed keeps food frozen for many hours, often up to a day or two depending on the model (check the leaflet for its "holding time"). Note when the power went off and call 105 to report it. Afterwards, food that still has ice crystals can usually be refrozen; food that has fully thawed should be cooked and eaten soon or thrown away. If in doubt, throw it out. Never bring a generator or barbecue indoors.

The first 3 steps

Do not open the freezer or the fridge: every opening lets warm air in.
Check the appliance leaflet or label: its holding time in a power cut is given in hours.
Note when the power went off, and call 105 or check your network operator's website for an estimated restore time.

Stop: danger

Never use a generator, barbecue or camping heater indoors or in a garage: carbon monoxide can kill. Headache or nausea in several people at once: get outside and call 999.
Food that has thawed for a long time, or smells or looks wrong: throw it away, do not taste it. Vomiting, fever or severe diarrhoea after a meal: call NHS 111, or 999 in an emergency.

During the power cut

Keep doors closed. A full freezer stays cold longer than a half-empty one.
If the cut is long, you can wrap the freezer in blankets, keeping vents clear, and keep it closed.
Eat chilled food from the fridge first.

After the power cut: keep or throw away

Still hard, with ice crystals: it stayed frozen; it can usually go back in the freezer.
Fully thawed but still cold: do not refreeze raw. Cook it thoroughly and eat it soon, or cook and then freeze.
Thawed and warm, or no idea how long: throw it away, especially meat, fish, dairy and ready meals.
Fridge: chilled food that has been warm for several hours is risky; the Food Standards Agency's page explains what to keep and what to throw.

What not to do

Opening the freezer every hour "to check".
Refreezing raw food that has fully thawed.
Tasting food to decide if it is still good.

Good to know

Keep a freezer thermometer: when the power comes back, it tells you if the freezer stayed cold (it should be at -18°C or below).
Ice packs and frozen bottles of water fill gaps and keep the cold longer.
If someone at home needs to keep medicines cold or relies on medical equipment, join your supplier's free Priority Services Register.

Who pays?

Network power cut: if it lasts longer than Ofgem's guaranteed standards, you may be entitled to a fixed payment from the network operator. See Ofgem's page for current amounts and how to claim.
Spoiled food: some home insurance policies cover freezer contents: check yours.
Only your home has no power: check your consumer unit first; see our guide "Power cut at home".

In Bristol, the power goes off one evening during a storm. Hannah calls 105, which gives an estimated fix of about four hours. She leaves the freezer shut. When the power returns, the thermometer shows the freezer stayed cold and everything is still hard: she keeps it all.

A made-up story, for illustration.

Bobby

Sources, verification, confidence

Verified on 18 October 2026, for England. Confidence: high for keeping doors shut, the 105 number and the no-refreezing rule; medium for holding times, which depend on each freezer (check the leaflet). Payment amounts are not quoted: see Ofgem. This guide describes common cases, not a diagnosis.